Fluid holding tank



FIG. 1 is a perspective view of a fluid holding tank, showing my new design;

FIG. 2 is a front-elevational view thereof;

FIG. 3 is a bottom-plan view thereof;

FIG. 4 is a top-plan view thereof; and

FIG. 5 is a side-elevational view thereof, the opposite side being a mirror image of that shown. 

The ornamental design for a fluid holding tank, as shown and described. 